Investigators have shown that infusion of 5cc of a 2% concentration of liquid lidocaine into the inside of the uterus can reduce the pain that is associated with other procedures, such as biopsies done of the lining of the uterus. The investigators seek to determine if a similar infusion made before IUD placement may reduce pain. Because pain is a subjective complaint and because plastic tubing is being used to sound the uterus instead of the usual metal probe (a uterine sound), the investigators have included a placebo arm with saline infusion. All women will receive oral medication in advance of IUD placement, so no woman will be subject to placebo only.